Photographic dye image stabilizer-solvent

ABSTRACT

A PHOTOGRAPHIC ELEMENT UTILIZING A COLOR COUPLER COMPOUND DISSOLVED PRIMARILY IN A STERICALLY HINDERED PHENOL EXEMPLIFIED BY A CHROMAN - 6 - OL; A SILVER HALIDE EMULSION CONTAINING SUCH A DISSOLVED COUPLER COMPOUND AND A METHOD FOR UTILIZING THE ELEMENT OR EMULSION TO OBTAIN DURABLE PRODUCTS HAVING REDUCED BULK AND GOOD IMAGE STABILITY TO LIGHT.

United States Patent @ffice Patented Oct. 17, 1972 3,698,909 PHOTOGRAPHIC DYE IMAGE STABILIZER- SOLVENT Gregory James Lestina and Max Herman Stern, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y. N Drawing. Filed Aug. 12, 1970, Ser. No. 63,270

Int. Cl. G03c 1/40 U.S. Cl. 96100 24 Claims ABSTRACT OF THE DISCLOSURE This invention relates to the field of color photography, particularly to a method for effecting improved stabilization of a color photographic dye or dye image, particularly a magenta dye, while maintaining a low bulk, durable photographic element containing a dye image.

It is known in the art that indophenol, indo aniline, azo, and azo methine dyes can be given some measure of protection against actinic radiation by admixing with various phenolic-type compounds having a fused heterocyclic ring system. Such additive compounds when used for photographic purposes are generally incorporated in a photographic element in the image-forming layer (1) as a disperision in a known solvent, or (2) in combination with a photographic color image-forming coupler and a known solvent.

Generally, a dispersion is made by dissolving the active stabilizer in a suitable art-recognized solvent such as di-n-butyl phthalate, and adding to a gelatin solution. The resulting mixture is then milled in a colloid mill.

Typical examples of the preparation, incorporation, and use of such image stabilizer additive compounds are found, for instance, in Lestina et al., U.S. Pat. 3,432,300.

It is known that a substantial amount of stabilizer is normally required in order to achieve desired light-stable photographic images. Concentrations of up to two moles of stabilizer per mole of coupler are not unsuual for this purpose. When dealing in the upper concentrations with the usual solvents, however, the resulting product may be swollen and less than satisfactory with respect to various physical properties. It is noted, for instance, that the stabilized photographic element tends to be substantially softer and less durable than the corresponding unstabilized element. There is also a tendency for the gelatin of such photographic elements to become porous and subject to frilling during subsequent photographic processing. In addition, many known image stabilizer compounds have a relatively high melting point and easily recrystallize before or during coating operations, when minimal amounts of solvent are utilized. This leads to plugging of equipment and also results in additional defects in the product such as streaking or incomplete coating.

It is an object of the present invention to produce novel color photographic elements capable of forming light-stable color images.

It is a further object of the present invention to obtain durable novel color photographic elements which possess improved dye image stability to actinic light and also possess durability plus reduced weight, bulk, and profile.

It is an additional object of the present invention to readily solubilize couplers and avoid premeature crystallization of image dye stabilizers by a novel method.

In addition, it is a specific object of the present inveniton to minimize streaking, frilling and surface defects in the stabilized color photographic element by a new technique.

These and further objects are accomplished through the present invention, which is characterized by using a solvent-stabilizer system comprising a class of sterically hindered phenols acting both as coupler solvent and stabilizer. The coupler solvents of the present invention are hydrophobic in nature and can be utilized alone or in admixture, and with removable auxiliary solvents, but require a single or combined melting point no higher than about C. Such a system preferably remains liquid at room temperature or slightly above.

The solvents utilized in the instant invention may act in the general capacity of coupler solvents in the manner of the high boiling-hydrophobic photographic coupler solvents described in the prior art. Examples of such solvents and their method of utilization may be found, for instance, in U.S. Pat. 2,304,939 of Mannes et al.

In addition, the solvent-stabilizer may be separately incorporated into the photographic element, as hereinafter defined. A similar improvement in image dye stability will result in either case. A removable auxiliary solvent is also, sometimes useful in practicing the present invention.

The sterically hindered phenolic coupler solvents uti lized in the present invention are conveniently described by the formula wherein A is a substituted phenyl radical, including a phenyl having a fused heterocyclic group in the 4-5 position relative to the OH group. More specifically, A is defined as the residue of a hydroxy phenyl ether, such as a p alkoxy m alkyl phenyl and a p-oxyisobornyl-substituted phenyl; a 6 hydroxy chroman; a S-hydroxy coumaran; and a hexahydro dibenzo furan-S-ol radical.

The solvent system utilized in the present invention can be further described as comprising at least one compound of the formulae wherein R, and R are individually defined as a hydrogen, alkyl, including cyclo alkyl, and alkoxy. These include linear and branched alkyl of 1-20 carbon atoms, particularly lower alkyl, and cyclo lower alkyl. The above-listed 3 ring substituents include, for instance, methyl, butyl, 2,2-dimethylbutyl, octyl, dodecyl, octadecyl, eicosonyl, cyclooctyl and cyclopropyl radicals. One or more of the alkyl, cycloalkyl or alkoxy radicals can be further substituted, for example, with hydro-xyl, halo, carboxyl, carbalkoxy, acyloxy, sulfo, sulfonyloxy amido, alkoxy, aryl, and aryloxy groups. Such further substituents include chloro, methoxy, octyloxy, carbomethoxy, CH COO-- phenyl, naphthyl pheno-xy and naphthoxy groups. R is additionally defined as an alkylene, particularly lower alkylene such as a 4 lower alkyl pentene-3, and not more than one of R and R is defined as hydrogen in compound I. R is defined as an alkyl, such as a linear or branched alkyl of 1-22 carbon atoms, including cycloalkyl, particularly cyclolower alkyl of 3-8 ring carbons, and an isobornyl radical. Included within R are methyl, propyl, isopropyl, t-butyl, octyl, dodecyl, octadecyl, n-docosanyl, cycloactyl, cyclopropyl, and the isobornyl radical; R are individually defined as a hydrogen or alkyl such as methyl, ethyl, octyl and dodecyl; and R is defined as a hydrogen, lower alkyl, and

I'f-Alk Ar 1%I-Ar Alk wherein Ar is an aryl radical such as a phenyl, naphthyl,

which may be further substituted on the ring by alkyl, halo or alkoxycarbonyl radicals; and Alk is defined as an alkyl radical, particularly lower alkyl. Z is also defined as a nitrogen-containing -6 membered heterocyclic radical of the formula particularly a ringed radical exemplified by piperidyl, pyridyl, pyrrolidyl, quinolino, tetrahydropyranyl etc.;

Z also represents -O-Ar or O-Alk as above defined.

The number and weight of the alkyl groups substituted on the above rings are varied, depending upon the particular diflfusion and solubility characteristics desired; the preferred ring substituents, for purposes of the present invention, are methyl, isopropyl, t-butyl, t-octyl, n-octadecyl and the corresponding further-substituted alkyl groups in which the alkyl moiety is substituted, for instance, by hydroxyl, halo, carboxyl, carbalkoxy, acetoxy, sulfo, acetamido, benzamido, methoxy, butoxy, dodecyloxy, phenoxy and naphthoxy groups.

The compounds utilized as the solvent-stabilizers of the present invention can be prepared, for instance, by (1) reacting an appropriate substituted phenol with a diene, terpene, or enol ether in the presence of a Lewis acid such as zinc chloride; or (2) by reacting an enamine with a quinone.

Additional detail and alternative procedures for preparation of such compounds can be found, for instance, in

Brannock et al., US. Pat. 3,184,457, Lestina et al., US. Pat. 3,432,300.

Exemplary solvent-stabilizer compounds of the present invention include:

(1 2,2-dimethyl-4-methyl-6-hydro-xy-7-octyl-chroman (2) 2,2-dimethyl-4-isopropyl-6-hydroxy-7-octyl-chroman (3) 2-methyl-2-(4,8-dimethyl)nonyl-6-hydro-xy-7- (or-8-)-octyl-chroman (4) Z-(N-methyl-N-phenyl)amino-3,3-dirnethyl-5- hydroxycoumaran (5) 2-methyl-2-hexadecyl-6-hydroxy-7-t butyl-chroman (6) 2,2-dimethyl-4-isopropyl-S-methyl-6-hydroxy-7- methyloxy chroman (7) 2,2,4,5-tetramethyl-6-hydroxy-7,S-dimethoxychroman (8) Z-methyl-2-hexadecyl-6-hydroxy-8-t butyl chroman (9) 2-methyl-2- 4,8-dimethyl nonyl-5-methyl-6-hydroxy- 7,8-dimethoxy chroman (10) 2-methyl-2(4,8-dimethyl)nonyl-6-hydroxy-7-t butyl chroman (l l) 2-(N-methyl-N-phenyl) amino-3,3-dimethyl-S-hydroxy-6-t butyl benzofuran (12) 2-hydroXy-3-0ctyl-5a-methyl-8-isopropyl-5a,6,7,8,9,

9a-hexahydrodibenzofuran l3) 2-t-octyl-4 dodecyloxy phenol (l4) 2-t-octyl-4-isobornyloxy phenol 15) Z-(y-carboxyethyl) -a-piperidino-3,3-dimethyl-5- hydroXy-6t-butyl coumaran (16) Z-[N-methyl-N-(p-carboxy methy1)benzyl] amino- 3,3-dimethyl-5-hydroxy-6-t butyl coumaran (17) Z-hydroxy-3-0ctyl-Sa-methyl-S-isopropyl-Sa,6,7,8,

9,9a-hexahydrodibenzofuran (18) 2-[N-methylN-(p-carboxy methyl)benzyl]amino- 3,3-dimethyl-5-hydroxy-6-t octyl courmaran (19) 2-hydroxy-5a-(N-methyl-N-phenyl) amino-5a,6,7,

8,9,9a-hexahydro dibenzofuran (20) 2-methyl-2- 4-methyl -3-pentenyl-6-hydroxy-7-t octyl chroman (21) 2,2,5 ,7,8-pentamethyl-4-isopropyl-6-chroman (22) u-Tocopherol (23) fl-Tocopherol (24) 'y-Tocopherol (25) B-Tocopherol The solvents of the present invention may be advantageously incorporated in a layer or in convenient proximity to a layer of a photographic element in which the dye image is produced and/or stored after formation. The term photographic element as here used may include a structure which comprises a supporting layer and one or more light sensitive layers in which the photographic color coupler compound and/or its solvent are (1) initially present or (2) introduced into the structure subsequent to exposure of the light-sensitive layer.

The present invention may 'utilize any of the wellknown image-forming elements and processes.

Compounds of the formula A-OH are etficacious in protecting dyes, including photographic masking dyes, and particularly dye images obtained by chromogenic development of S-pyrazolone couplers commonly used in photography, such as couplers for magenta dye formation.

Typical masking dyes are described, for instance, in the Encyclopedia of Chemical Technology, volume 5, pages 812-845 (1964) and in the article by Gauguin and Mac- Donald in The Journal of Photographic Science, volume 14 (1966), pages 260277.

Typical magenta dyes are produced by color development of couplers described, for instance, in US. Pats. 2,600,788, 2,725,292, 2,908,573, 3,006,759, 3,062,653, 3,152,896, 3,311,476 and US. application Ser. No. 458,455 of Young, filed May 24, 1965.

Cyan dye-forming couplers are exemplified in US Pats. 2,474,293, 2,275,292, 2,895,826, and 2,908,573, and produce cyan dyes upon chromogenic development, such couplers typically being phenolic compounds, including a-naphtholic compounds. The resulting dyes and dye images are advantageously stabilized against light exposure by applicants stabilizing compounds.

Yellow dye-forming couplers, such as found in U.S. Pat. 2,908,573, produce photographic dyes that are made less subject to fading upon prolonged exposure to actinic light by the utilization of the present stabilizer solvents. Typical yellow couplers include ketomethylene compounds.

As earlier indicated, the active stabilizer-solvent compounds of the present invention can be utilized individually, or in combination, as replacement for known highboiling organic couplers solvents of the type described in US. Pats. 2,304,939 and 2,322,027.

In practicing the present invention it is also sometimes found useful to employ removable low boiling or water soluble auxiliary solvents such as ethyl acetate to aid or effect the initial solution of the coupler compound. Such solvents are described and exemplified, for instance, in US. Pats. 2,801,170, 2,801,171, and 2,949,360.

In general, a liquid solvent system comprising substantially one or more compounds of the formula A-O'H is utilized in active amounts ranging from about one-tenth to about five times by weight of organic dye forming coupler compounds to be solubilized. A preferred range for this purpose is from about one-half to two times the weight of coupler.

The term a support as here utilized includes known photographic support layers such as cellulose acetate, polyterephthalate etc. bases, as disclosed, for instance, in chapter 3, pages 47-56 of Emulsion Chemistry by Duffin (1966), and herein incorporated by reference. The term as de fined includes paper or other fibrous material coated with a hydrophobic film or surface which repels and does not absorb or adsorb water.

Supports having a hydrophobic surface used to advantage in the present invention include hydrophobic resins which may be electron bombarded as described, for instance, in British Pats. 971,058 and 1,060,526 and U.S. Pats. 2,864,755 and 2,864,756 to improve adhesion of hydrophilic colloid layers coated over them. Such resin films are either self supporting or may be coated over another support layer. Specific supports having useful hydrophobic surfaces include electron bombarded poly- (ethylene terephthalate) films (i.e. those electron bombarded to have a contact angle less than 45 C.) in accordance with the process described in US. Pat. 3,220; 842; also an electron-bombarded surface comprising a chromium halide complex such as a sterato chromic chloride electron-bombarded by the process as described in US. Pat. 3,117,865; or electron bombarded hardened gelatin coatings (i.e. hardened gelatin coated papers electron bombarded by the process described in Belgian Pat. 671,661). Other suitable hydrophobic support surfaces which can be electron bombarded included poly-u-olefins, preferably derived from olefins containing from 2 to carbon atoms (e.g., polyethylene, polypropylene, poly(3- methylbutene-l), poly(octene-l), poly(decene-1), etc.); polyamides; polyacetals; polycarbonates; and cellulose esters and ethers, e.g., cellulose triacetate, cellulose acetate butyrate, ethyl cellulose, etc.

The hydrophobic material, for example, a poly-a-olefin is coated on the paper by any of the methods commonly used such as by extrusion of a melt of the polya-olefin, coating of a solvent solution of the poly-a-olefin. The support may also contain various functional additives such as pigments (titanium dioxide) and an antistatic agent as described, for instance, in US. Pat. 3,253,922.

Our invention is further illustrated by the following examples.

EXAMPLE 1 To a mixture of acetic acid ml.), n-octyl hydroquinone (22.2 g., 0.1 mole), and .2 g. of zinc chloride is 6 added 2,5-dimethyl-2,4 hexadiene (8.6 g., 0.1 M), and the resulting mixture maintained at 60 C. for 2 hours. Two drops of concentrated sulfuric acid is added and the heating continued for 10 minutes. The mixture is then added slowly to 500 ml. of cold water and the yellow oily product separated and molecularly distilled to obtain 17 g. of the 2,2-dimethyl-4-isopropyl-6-hydroxy-7-octylchroman having a melting point of 16 C. (cpd. 2, supra).

EXAMPLE 2 To a slurry of quinone (5.4 g., 0.05 mole) in 50 m1. of benzene is slowly added a solution of N-methyl-N- phenyl isobutenyl amine (8.35 g., 0.05 mole) in 25 ml. of benzene, with cooling at 40-50 C. The reaction mixture is left at room temperature for about 12 hours and the resulting solid product filtered and purified by recrystallization from benzene to obtain 6 g. of a product having a melting point of 7072 C. (cpd. 4).

EXAMPLE 3 2,3-dimethoxy hydroquinone and 2,7,11-trimethyl-1- dodecene-3-ol are reacted in accordance with the process of Example 1 to obtain a product having a boiling point of 128 C./l,u. (cpd. 9).

EXAMPLE 4 To a slurry of .05 mole t-butyl quinone in 50 ml. benzene is slowly added a .05 molar solution of N-methyl-N-phenyl isobutenyl amine in 25 ml. benzene in the manner of Example 2. The resulting liquid product has a boiling point of /2,LL (cpd. 12).

EXAMPLE 5 A mixture of acetic acid, t-butyl hydroquinone and zinc chloride and dodecene are reacted in general accordance with the process of Example 1 but at a temperature of 20-25 C. for 12 hours to obtain the 2-t-octyl-4-dodecyloxy phenol having a B.P. 182-183/.5 mn. (cpd. 13).

EXAMPLE 6 A slurry of t-octyl quinone in benzene is added to N-methyl-N-phenyl ethenyl amine in accordance with the process of Example 2 to obtain 2-hydroxy-5-a-(N- methyl N phenyl amino) 5a,6,7,8,9,9a hexahydro dibenzofuran product (B.P. 240/ 1,11. (cpd. 19).

EXAMPLE 7 (A) A single layer test film strip is prepared b dissolving 50 mg. of l-(2,4-dimethyl-6-chlorophenyl)-3-[3- {cc-(In pentadecyl phenoxy)-butyramido}-benzamido]-5- pyrazolone magenta coupler in di-n-butyl phthalate (coupler solvent Y). The solution is added to an 8% gelatin solution, milled in a colloid mill, admixed with silver chlorobromide sensitized to green light, and coated onto a celluolse acetate film base. The coupler compound and procedure are described, for instance, in Example 1 of US. Pat. 3,432,300 Lestina et al.). The resulting green-sensitive strip contains 50 mg. analyzed silver 250 mg. gelatin, plus 50 mg., respectively, of the coupler and solvent (Y) per square foot of coating.

(B) The film strip of A is again prepared utilizing the same amount of coupler compound dissolved in 25 n1g./ft. of solvent Y and 25 mg./ft. of a compound of the formula The procedure of A and B, supra, is followed using 50 mg./ft. of cpd. 1 as exclusive solvent for the coupler compound.

Film strips A-C, as described, are exposed to green light through a continuous carbon wedge and developed in the usual manner as described, for instance, in column 8, process D of Bard et al., US. Pat. 3,189,452. The developed strips exhibit substantially identical photographic and physical properties with respect to speed, fog, contrast, and D Film strips A-C, are then tested for fading by exposure to the simulated equivalent of an average north skylight for 252,000 foot candle hours (f.c.h.) as described, for instance, in column 6, lines 34-43 of Lestina et al., US. Pat. 3,432,300. The amount of fading is then measured at the peak wave length from a density of 1.0.

Samples AC exhibit 86%, 37% and 25% fading respectively.

EXAMPLE 8 Three test strips are prepared in the manner of Example 7 and identified, respectively, as samples A-C; these strips are identical with Example 7 A-C except for the substitution of a compound of the formula 0H cpd. 2

I (M.P. l0 C.)

in place of cpd. 1 in the B and C film strips. The photographic and physical qualities obtained are substantially the same as obtained in samples 7 A-C, and the dye fading is found to be 86% (Control), 31% (B), and 19% (C) respectively.

EXAMPLE 9 Example 7 is repeated, utilizing the above-listed cpds. 4, 9, 12, 13, 19, 22 and 25 as joint solvents in equal amounts with solvent Y (strip B) and as exclusive coupler solvents; the test result is indicated in Table A, wherein X denotes one of the 7 above-listed compounds.

TABLE A Control Solvent strip Y (25 mg.) with Compound Compound 50 mg. Y, X (25 mg), X (50 mg), percent percent percent fade fade fade EXAMPLE 10 Example 7 is repeated using a multilayer camera-speed color negative film processed in accordance with the method described as Process A of Bard et al., US. Pat. 3,189,452. Substantially the same relative dye image stability is obtained.

8 EXAMPLE 11 Example 7 is repeated using a multilayer camera-speed color reversal film, which is processed as described in Example 2 of Henn et al., US. Pat. 2,984,567, and substantially the same relative dye stability is demonstrated.

EXAMPLE 12 Example 8 is repeated, substituting one of the following developing agents in place of 4-amine-3-methyl-N- ethyl-N-fl-(methanesulfonamido)ethyl aniline sesquisulfate hydrate:

(a) 4-amino-3-methyl-N-ethyl-N-fl-hydroxyethyl aniline sulfate,

:(b) 4-amino-N-ethyl-N-B-hydroxyethylaniline sulfate,

(c) 4-amino 3 methyl-N,N-diethylaniline hydrochloride, and

'(d) p-amin0-N,N-diethylaniline hydrochloride.

The film strips are tested for fading in accordance with Example 7 and the relative amount of fading in strips A-C found to be substantially the same.

EXAMPLE 13 Example 8 is repeated, substituting a bleach-fix step as described by K. I. Jacobson in British Pat. 991,412, subsequent to color development in place of the usual bleachthen-fix steps. The film strips exhibit substantially the same relative stability as obtained in strips A-C of Example 8.

EXAMPLE 14 Two film strips identical to Example 7 are prepared but substituting a higher melting 7-tertiary octyl isomer of cpd. 1 having the formula H l I CH3 Film strip A utilizes 25 mg./ft. of the tertiary butyl isomer and an equal amount of solvent Y to dissolve the color coupler compound. Strip B utilizes 25 mg./ft. of solvent Y and an equal amount of the above 7-tertiary octyl isomer, and 25 mg. ethyl acetate as an auxiliary solvent, this melt immediately being applied to the sup port. Strip C utilizes 25 mg./ft. of the tertiary octyl isomer of cpd. 1 plus 25 mg./ft. of ethyl acetate as an auxiliary solvent, this melt being chilled, noodled and stored for one week in a refrigerator and then remelted and held at 45 C. for one hour and applied to the support. Strip A is found to be substantially identical with strip A of Example 7. Strip B exhibits moderate frilling and streaking plus deformation of the photographic image. Strip C contains broad strips lacking emulsion coverage of the film base resulting from extensive recrystallization of the coupler compound.

The invention has been described above in detail with reference to particular preferred embodiments but numerous variations and modifications thereof fall within the spirit and scope of the present invention as defined in the following claims.

We claim:

1. A photographic element comprising a support having coated thereon at least one light-sensitive silver halide emulsion, said element containing a photographic coupler compound dissolved in a liquid solvent system consisting essentially of one or more non-coupling compounds of the formula having a single or combined melting point of up to 100 C.; wherein A is defined as a member selected from the group consisting of a p-isobornyl-oxy-phenyl, a chroman having the OH substituent attached in the 6-position, a coumaran having the OH substituent attached in the 5- position and a hexahydro dibenzofuran-S-ol.

2. The photographic element of claim 1 in which A-OH is a compound of the formulae R and R are indivadually defined as a hydrogen, alkyl or alkoxy, R being additionally defined as an alkene; R is defined as a hydrogen, alkyl, alkoxy and aryl group; R are individually defined as a hydrogen or alkyl; R' is defined as a hydrogen, lower alkyl or I IAr I Alk wherein Ar is a phenyl, naphthyl or benzyl radical, and Alk is an alkyl; and Z is defined as -N-Ar a nitrogen-containing 5-6 membered heterocyclic radical, OAr, or -O-Alk, wherein Ar is a phenyl, naphthyl or benzyl radical and Alk is an alkyl.

3. The photographic element of claim 1 wherein AOH is a compound of the formulae II. R

l R: R1 OH? I R6 or I R \I; R2 I in which R is H or alkyl;

R is hydrogen or lower alkyl; R is alkyl or lower alkene; R are lower alkyl; and Z is 1]IAr or I Alk wherein Ar is a benzyl radical, Alk is lower alkyl, and

is a N-containing 5-6 membered heterocyclic radical.

10 4. The photographic element of claim 1 wherein A-OH is a compound of the formula l 4--R2 Bl in which R and R are individually defined as a hydrogen, alkyl or alkoxy;

R are defined as a hydrogen, or alkyl, R being additionally defined as lower alkene; and

R is defined as a hydrogen, alkyl, alkoxy or aryl group. 5. The photographic element of claim 1 wherein AOH is a compound of the formula in which R, R and R are individually defined as a hydrogen or alkyl; and

Z is defined as -NAr Alk

or a nitrogen-containing 5-6 membered heterocyclic radical, wherein Ar is a phenyl, naphthyl or benzyl radical and Alk is an alkyl group.

6. The photographic element of claim 4 wherein R is n-octyl; R is hydrogen; R is methyl or isopropyl; R and R are methyl; and R is hydrogen.

7. The photographic element of claim 4 wherein R is n-octyl; R is hydrogen; R is isopropyl; R are methyl; and R is hydrogen.

8. The photographic element of claim 4 wherein R and R are hydrogen; R is an alkyl of 1-16 carbon atoms; and R are methyl.

9. A photographic silver halide emulsion containing at least one photographic color coupler compound dissolved in a liquid solvent system consisting essentially of one or more non-coupling compounds of the formula wherein A is defined as a member selected from the group consisting of a p-isobornyl oxyphenyl, a chroman having the OH substituent attached in the 6-position, a coumaran having the OH substituent attached in the 5-position and a hexahydro dibenzofuran-S-ol.

10. The photographic emulsion of claim 9 which AOH is a compound of the formulae 1 1 in which R is H or alkyl; R is hydrogen or lower alkyl; R is alkyl or lower alkene; R are lower alkyl; and Z is wherein Ar is a benzyl radical, Alk is lower alkyl, and

is a N containing 5-6 membered heterocyclic radical.

11. A photographic emulsion of claim 9 in which AOH is in which R and R are individually defined as a hydrogen alkoxy or alkyl; R are defined as a hydrogen, or an alkyl radical; and R is defined as hydrogen, alkyl, alkoxy or aryl.

12. A photographic emulsion of claim 9 in which AOH is in which R, R and R are individually defined as a hydrogen or alkyl; and

Z is defined as or a nitrogen-containing 5-6 membered heterocyclic radical, wherein Ar is a phenyl, naphthyl or benzyl radical and Alk is an alkyl group.

13. A method for obtaining a durable color photographic element of minimal weight and good dye image stability to light, comprising utilizing as a light sensitive silver halide emulsion layer of said element a silver halide gelatin emulsion having dispersed therein droplets comprising a color photographic coupler substantially dissolved in a solvent system having a melting point of up to 100 C. and consisting essentially of one or more noncoupling compounds of the formula wherein A is defined as a radical selected from the group consisting of a p-isobornyl oxyphenyl, a chroman having the OH substituent attached in the 6-position, a coumaran 1 2 14. The method of claim 13 wherein AOH is a compound selected from the group consisting of I. OH II. R1

R and R are individually defined as a hydrogen, alkyl or alkoxy radical, R being additionally defined as an alkene;

R is individually defined as a hydrogen, alkyl, alkoxy and aryl;

R is individually defined as hydrogen or alkyl;

R is defined as lower alkyl or I'll-Ar Alk wherein Ar is a phenyl, naphthyl or benzyl radical, and Alk is an alkyl; and Z is defined as l N-Ar Alk or a nitrogen-containing 5-6 membered heterocyclic ring, wherein Ar is a phenyl, naphthyl or benzyl radical and Alk is an alkyl.

15. The method of claim 13 comprising initially dissolving said photographic color coupler compound into a liquid solvent system containing at least one compound of the formula and incorporating the resulting solution into a silver halide emulsion layer in said photographic element.

16. The method of claim 15 wherein the solvent system consists essentially of at least one compound of the formula and an auxiliary solvent.

17. The method of claim 13 wherein AOH is a compound of the formula in which R and R are individually defined as a hydrogen alkoxy or alkyl;

R are defined as a hydrogen, or an alkyl radical; and

R is defined as hydrogen, alkyl, alkoxy and aryl.

13 18. The method of claim 13 wherein AOH is a compound of the formula in which R, R and R are individually defined as a hydrogen or alkyl; and Z is defined as --N-Ar Alk or a nitrogen-containing 5-6 membered heterocyclic radical, wherein Ar is a phenyl, naphthyl or benzyl radical and Alk is an alkyl group.

19. The method of claim 13 wherein AOH is a compound of the formula R, R R and R are individually defined as a hydrogen or alkyl radical; and R' is defined as lower alkyl or I IAr l klk wherein Ar is a phenyl, naphthyl or benzyl radical, and

Alk is an alkyl.

20. The method of claim 17 wherein R is hydrogen; R is methyl or isopropyl; R and R are methyl; R is hydrogen and R is n-octyl.

21. The method of claim 17 wherein R is n-octyl, R is hydrogen; R is isopropyl; R are methyl and R is hydrogen.

22. The method of claim 17 wherein R and R are hydrogen; R is an alkyl of 1-16 carbon atoms; and R are methyl.

23. A photographic element comprising a support having coated thereon at least one light sensitive silver halide emulsion, said element containing a photographic coupler substantially dissolved in a compound of the formula OH R1 R \O/ Rs in which R, R R and R are individually defined as a hydrogen, alkyl or alkoxy group; R' is defined as lower alkyl or R, R R and R7 3 are individually defined as a hydrogen or alkyl radical; and 'R is defined as lower alkyl or I lib-Ar Alk wherein Ar is a phenyl, naphthyl or benzyl radical, and Alk is an alkyl radical.

References Cited UNITED STATES PATENTS 2,835,579 5/1958 Thirtle et al. 96-100 3,062,653- 11/1962 Weissberger et a1. 9610O 3,184,457 5/1965 Brannock et al. 252-402 3,432,300 3/1969 Lestina et al 96-56 3,519,429 7/ 1970 Lestina 96-56 J. TRAVIS BROWN, Primary Examiner US. Cl. X.R. 

